Campodelphys, Kim & Boxshall, 2020

Kim, Il-Hoi & Boxshall, Geoff A., 2020, Untold diversity: the astonishing species richness of the Notodelphyidae (Copepoda: Cyclopoida), a family of symbiotic copepods associated with ascidians (Tunicata), Megataxa 4 (1), pp. 1-6 : 590-591

Campodelphys gen. nov.

Diagnosis. Bodycaterpillar-like, elongate, cylindrical. Prosome unsegmented or with constrictions between somites: cephalosome lacking defined dorsal shield, bearing paired ventral tubercles posterolaterally. First to third pedigerous somites short: fourth pedigerous somite expanded posteriorly, incorporatingfifth pedigerous somite. Freeurosome much smaller than prosome, 5- segmented, comprising genital somite and four free abdominal somites. Caudalramus short, armedwith 6 setae. Rostrum distinct. Antennule stout, obscurely segmented. Antenna 3-segmented, consistingof coxa, basis, and unsegmentedendopod bearing terminal claw. Labrum not specialized. Mandible consisting of coxa and biramous palp; coxal gnathobase with pectinate medial margin; exopod with 4 setae; endopod with 1 setaon first segment and 3 or 4 setae on second. Maxillule and maxilla each represented by lobe bearing setae. Maxilliped 1- or 2-segmented, bearing 1 or 2 setae distally or subdistally. Legs 1–4 biramous, located anteriorly on prosome, separated by regular gaps; legs broad with short rami; protopods unsegmented or incompletely 2-segmented; exopods 2-segmented; endopods 1- or 2-segmented. Setae on rami short, usually bluntly tipped. Inner distal seta on basis of leg 1 present or absent. Leg 5 absent or represented by 1 or 2 small setae.

Type species. Campodelphys hirsutus gen. et sp. nov. by original designation.

Otherincluded species. Campodelphysbullatus gen. etsp. nov., C. stocki gen. etsp. nov., C. ancylocephalus gen. etsp. nov., and C. seticoxus gen. etsp. nov., describedbelow.

Etymology. The name is derived from the Greek camp (=caterpillar) and - delphys, referring to the typically caterpillar-like body form of the genus. Gender masculine.

Remarks. Campodelphys gen. nov. resembles both Procampodelphys gen. nov. and Prophioseides in the body form of the adult female. Prophioseides can be excluded from further detailed comparisons with the new genus because it has a denticulate coxal gnathobase on the mandible, whereas the new genus has a pectinate medial margin on the gnathobase

In Campodelphys gen. nov. the swimming legs each have a 2-segmented exopod and a 1- or 2-segmented endopod, and both rami are broad and armed with thick, spiniform setae. In Procampodelphys gen. nov. the swimming legs are much reduced and narrow, with the unsegmented, lobate rami bearing fewer setae. In contrast to the relatively complex condition of the swimming legs, the mouthparts of Campodelphys gen. nov. are much more reduced, with both the maxillule and maxilla represented by setose lobes and the maxilliped is armed only with 1 or 2 setae. These differences serve to clearly differentiate between members of these two genera. In the form of the swimming legs, Campodelphys gen. nov. more closely resembles Scolecodes Illg, 1958 than any other genus, although these two genera can be easily distinguished by a range of other characters. The five species of Campodelphys gen. nov. described below may be distinguished by the following key.

Key to species of Campodelphys gen. nov. based on adult females.

1. Legs 2–4 with 2-segmented endopods ............................. 2

Legs 2–4 with 1-segmented endopods ............................. 3

2. Anal somite lacking spinulose ventral lobes; second endopodal segment of mandible armed with 3 setae; maxilla with 4 setae .............................. C. hirsutus gen. etsp. nov.

Anal somite with spinulose ventral lobes; second endopodal segment of mandible with 4 setae; maxilla with 6 setae .... ................................................. C. bullatus gen. etsp. nov. 3. Maxillule with 6 setae; maxilliped with 1 seta; endopod of leg 2 with 6 setae; leg 5 represented by 1 small seta .......... ..................................... C. ancylocephalus gen. etsp. nov. Maxillule with 7 setae; maxilliped with 2 setae; endopod of leg 2 with 8 setae; leg 5 represented by 2 small setae ...... 4 4. Maxilla armed with 7 setae; leg 1 with 2-segmented endopod; coxa of leg 4 lacking inner seta .......................... .................................................... C. stocki gen. etsp. nov. Maxilla armed with 6 setae; leg 1 with 1-segmented endopod; coxa of leg 4 with inner seta ............................... ............................................... C. seticoxus gen. etsp. nov.